Prior art searches were conducted for graphene/carbon or graphene/graphite electrochemical double layer electrodes. Only one reference suggests coating carbon with graphene. Several references include graphene, activated carbon and graphite individually as possible components of electrochemical double layer electrodes but do not suggest a combination of the same, or any benefit of such combinations. Further, none of the prior art references deal with a wet process for preparing carbon papers for use in electrodes using such combinations of carbon.
In U.S. Patent publication 2012/0088156A, entitled METHOD FOR MANUFACTURING POSITIVE ELECTRODE ACTIVE MATERIAL FOR ENERGY STORAGE DEVICE AND ENERGY STORAGE DEVICE, there is taught a multistep method to produce electrodes that includes adding graphene oxide to an electrode mixture and reducing the graphene oxide to graphene. One of the dependent claims includes adding less than 1% conductive auxiliary agent that may be carbon black.
U.S. Pat. No. 7,907,387 entitled ELECTRODE FOR ENERGY STORAGE SYSTEMS, PRODUCTION METHOD THEREOF AND ENERGY STORAGE SYSTEM COMPRISING SAID ELECTRODE, teaches using a slurry or ink of carbon active material to form a sheet, drying and adding an aluminum mesh current collector for electrochemical double layer capacitors.
U.S. Pat. No. 6,768,631 teaches a method for preparing porous carbon material, porous carbon material and electrical double layer capacitor using the same. This patent teaches a dry mixture of carbon materials calendared onto an aluminum mesh current collector for capacitors.
Http://digitaleprints.um.edu.m/1978/7/CH6.pdf teaches the use of carbon black in slurry applied to aluminum mesh for capacitors.
The process and electrode materials of the instant invention are distinct from any of the prior art materials. Never is it suggested that the active material is an activated carbon enhanced with graphene. The use of carbon materials with an aluminum mesh is not unique, but the manufacture of a semi-dry film calendared onto an aluminum mesh is.